X-Git-Url: https://gerrit.opnfv.org/gerrit/gitweb?a=blobdiff_plain;f=kernel%2Farch%2Fx86%2Fkernel%2Fstep.c;h=0ccb53a9fcd9361b83c7acd26e1f64601816a3d1;hb=ec0a2ed6d8a5e555edef907895c041e285fdb495;hp=9b4d51d0c0d013274f7ba46c2e58319f0d1d9145;hpb=342fa5dfa053559f47caad657132522496dcf1b3;p=kvmfornfv.git

diff --git a/kernel/arch/x86/kernel/step.c b/kernel/arch/x86/kernel/step.c
index 9b4d51d0c..0ccb53a9f 100644
--- a/kernel/arch/x86/kernel/step.c
+++ b/kernel/arch/x86/kernel/step.c
@@ -5,6 +5,7 @@
 #include <linux/mm.h>
 #include <linux/ptrace.h>
 #include <asm/desc.h>
+#include <asm/mmu_context.h>
 
 unsigned long convert_ip_to_linear(struct task_struct *child, struct pt_regs *regs)
 {
@@ -27,13 +28,14 @@ unsigned long convert_ip_to_linear(struct task_struct *child, struct pt_regs *re
 		struct desc_struct *desc;
 		unsigned long base;
 
-		seg &= ~7UL;
+		seg >>= 3;
 
 		mutex_lock(&child->mm->context.lock);
-		if (unlikely((seg >> 3) >= child->mm->context.size))
+		if (unlikely(!child->mm->context.ldt ||
+			     seg >= child->mm->context.ldt->size))
 			addr = -1L; /* bogus selector, access would fault */
 		else {
-			desc = child->mm->context.ldt + seg;
+			desc = &child->mm->context.ldt->entries[seg];
 			base = get_desc_base(desc);
 
 			/* 16-bit code segment? */